the days are long but the months are short
The accelerated perception of time scares the shit out of me. This is the phenomena as you age that each year feels like it goes by faster. When you're 10, a year is just 1/10th of your life. When you're 20, a year is just 1/20th of your life and so on.
A related feeling is how each individual day feels more or less the same in length, but whole months can just fly by in a blink.
The days are long but the months are short.
I remember when summer vacation was an unfathomably long time. Three months to a second grader might as well be forever. And now almost 20 years later, my wife and I have had our second pup for 4 months now, she's been in her job for over a year, and I've been in grad school for 4 years. Time flies when you're getting older.
edit: the word is juvenoia. Bella wrote a much more eloquent post about this here